These are from a Bézique pack. Well, they're usually called "Bézique" packs when they're put up for sale as that sounds classy, but you need two of them to play Bézique; they're actually Piquet packs. Anyway, in such a pack there are only 32 cards in total (the 2s-6s of each suit are removed), which is what puts collectors off them.
It puts me off them, too, but this particular pack is manufactured by W. H. Willis and I don't have any other Willis packs in my collection. Willis & Co., the successor to Charles Steer, was based in London and operated 1869-1887. It started out printing cards with white faces for the picture cards, but introduced more expensive packs from around 1875 onwards that had coloured faces. These more expensive packs also had fancier designs on the backs.
You'll notice that my cards don't have corner indeces to indicate what the card is when held in the hand; Willis introduced these around 1880. A new, "triplicate" pack brought out in 1883 replaced these with an image of the whole card (minus the index) in miniature. I suspect that this innovation's failure to catch on might have been why Willis & Co. sold off its playing card business six years later and focused on making cardboard instead.
You'll notice that the Queen of Spades is unturned (the pip is on the right, not the left as it is in modern packs). All of Willis's packs were unturned, so this doesn't help date it. However, we do know that this particular pack is early because the pips on the non-face cards are all the same orientation; they were two-way for most of the company's lifetime. The Piquet deck came out in 1870, but the corners are rounded (which the very first ones weren't); we're probably looking at something manufactured 1872-1875, then.
It's rather grubbier than I'd have liked, but it came cheap and I'm sure that if I took it to BBC One's The Repair Shop and told them a sob story, some expert could make it come up a treat.